Cerebrix ("Plump" in the Korean version) is Chip's robot. Like its owner, Cerebrix possesses a more thought-focused logical personality rather than a feeling-based one. Bipedal, with no arms, it is equipped with advanced memory, sensory, computing and processing systems stored in its large head. It can also fly by means of a retractable propeller stored in an upper compartment of its head. One of its main functions include a huge sensory array and is also equipped with two antennae through which it can tap into almost any frequency and cause disturbances, creating confusion in its foes. Also its advanced probability computing system is capable of determining the outcomes of events before they occur. Its personality and speech are much more machine-like but what it has to say is usually very important.

In the original Korean version, Plump has a female personality and is voiced by Bae Ju-Young. In the 4Kids Entertainment English dub, Cerebrix has a male personality and is voiced by Jimmy Zoppi.